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QUI-1057
Page 24
Markes International Ltd
T:
+44 (0)1443 230935
F:
+44 (0)1443 231531
E:
www.markes.com
Status
Shows the overall status of UNITY 2 as it progresses through the various stages of
the sequence - Standby, Leak Test, Trap Heat etc. Status will also report tube
failures i.e. Tube Leaked.
Elapsed Time
Shows the time elapsed since the start of the function currently operating on UNITY
2 and should be read in conjunction with the Status parameter. For example if the
Status is reading Prepurge and the Elapsed Time is reading 0.3 this tells us that
UNITY 2 is 0.3 minutes (i.e. 18 seconds) into the ambient purge. If the Status is
reading Primary Desorb and the Elapsed Time is 4.9 - then it is 4.9 minutes since
the start of tube desorption etc.
Pressure
Shows the pressure of the carrier gas within the UNITY 2 flow path.
UNITY zones
UNITY 2 continually monitors the actual temperature of its internal heated/cooled
zones (tube oven, cold trap, transfer line and heated valve) and the actual carrier
gas pressure and compares them to the set values.
When first switched on UNITY 2 status changes to Standby and the display for UNITY
2 temperature will be highlighted blue until all zones reach the relevant set point.
The Purge Gas indicates whether the dry air or nitrogen is at a high enough pressure
for the Peltier coolers to operate. If Purge Gas is displayed as ‘Off’ then this
indicates that the purge gas pressure is not high enough. In this scenario the Peltier
coolers will be switched off.
NOTE
: A run may be started when UNITY 2 is Not Ready and the run will then pause,
waiting for the appropriate zone to reach temperature before desorbing the tube.
The status will read Equilibrating at this stage.
NOTE
: The actual temperature of the tube oven has no effect on the ready status as
heat is not applied to the oven until tube desorption starts.
GC
Indicates whether the GC status is ready (
) or not ready (
).
See Section 3.2.1 below.
3.2.1
External ready signal
UNITY 2 is connected to the GC via the relevant GC Interface Harness:
SERUTE-5142
Agilent GC
SERUTE-5143
Thermo GC
SERUTE-5144
Varian GC
SERUTE-5141
Other GC (including Shimadzu)
The analytical system should be configured such that all components "downstream" of the GC (e.g. mass
spectrometer, data handling system) must be ready before the GC becomes ready. This ensures that no
sample is injected from UNITY 2 onto the GC when the analytical system is not able to analyse the sample
and collect the data.
When the GC comes ready it will provide a signal to UNITY 2 via the Interface Harness and the GC indicator
on the status bar will change from a cross to a tick. UNITY 2 checks this signal, to ascertain whether the